1. Field of the Invention
The invention relates to an examination table, particularly in Nuclear Magnetic Resonance image detecting machines of the so-called dedicated type, i.e., designed for detecting images of specific body parts.
2. Discussion of Related Art
Currently, in the so-called dedicated Nuclear Magnetic Resonance image detecting machines, i.e. those designed for detecting images of specific body parts, and having an image detection cavity of such a size as to prevent the insertion of the whole body (like in the so-called total-body machines), the patient is asked to sit or lay down on a chair or on an examination table. The latter are of the conventional type, and have no particular construction characteristics to comply with specific functions, examinations and corresponding positions of the patient with respect to the machine and to the detection cavity. Therefore, prior art examination tables and chairs are not only very complex and expensive, in order to ensure that the patient always has the right position with respect to the detection cavity, but are also uncomfortable and inconvenient for patient positioning. The high costs and the uncomfortable and time-consuming positioning operations required by prior art equipment are the most significant drawbacks thereof.
The invention has an object to provide an examination table of the type described hereinbefore, which allows, by simple and inexpensive arrangements, for easy and fast patient positioning operations, requiring a minimum number of adjustments, without affecting the comfort of the patient during the image detection process.
The invention achieves the above objects by providing an examination table of the type described hereinbefore, which is included in dedicated machines for detecting Nuclear Magnetic Resonance images of specific body parts, and wherein the examination table has an at least one-degree-of-freedom constraint to the image detection machine, and has support means which allow the examination table to be moved in at least one, preferably two or more degrees of freedom.
In a preferred embodiment, the examination table is mounted is such a way as to be able to slide on a stationary guide, which is fixed with a predetermined orientation with respect to the detection cavity of the machine, and it may be further translated in both senses along said guide and rotated about an axis perpendicular to the direction it follows while sliding on the guide.
Particularly, the rectilinear translation guide is oriented in the direction of insertion/extraction of one part of the patient body in or from the detection cavity by a simple straight-line translation movement, while the examination table may be also rotated about an axis perpendicular to said translation direction.
Especially, the rectilinear guide is horizontal, while the axis of rotation of the examination table is vertical.
The examination table advantageously has three points of support, i.e., two wheels, at two corners of one end side thereof, said wheels being also rotatable about a vertical axis, and another point of support, coinciding with a vertical axis of rotation which corresponds to the median longitudinal axis at the opposite end side of the examination table.
The vertical axis of rotation is provided at the top of a supporting column, which has a lower carriage with at least three points of support, i.e. at least one central sliding wheel, associated to the guide, and at least two lateral wheels, touching the ground, and being also rotatable about a vertical axis.
Advantageously, there are provided at least two wheels associated to the guide, one behind the other in the median vertical plane of the examination table.
According to a further characteristic, the examination table has a stationary part, whose length substantially corresponds to the average length of the trunk, and an overturning extension, provided at one end, having the function of a footrest. The footrest may be overturned into a projecting position, in which it extends the examination table, and into a rest position, in which it is substantially parallel to, or possibly partially hidden in the corresponding end side of the examination table.
The examination table is anatomically curved, the curved region being moved towards the end side with the two wheels, i.e., in the area intended to receive the pelvis.
In the pelvis area, i.e., in the curved region, there is provided one removable armrest for each side.
The vertical axis of rotation of the examination able, corresponding to the third point of support hereof, is provided in the region associated to the upper back.
The substantially plane back-supporting area extends with a predetermined inclination with respect to the wholly horizontal orientation, i.e. with a rising inclination from the lowest zone of the hollow formed by the curve.
The opposite, much shorter branch, associated to legs, and provided with the overturning footrest, is also oriented with a certain rising inclination towards the end side of the examination table associated thereto.
Thanks to the arrangements described above, the examination table according to the invention has a very simple, stout, safe, comfortable and cost-effective construction. The parts to be jointed to the examination table are only the footrest, the wheels and the vertical axis of rotation. By connecting the examination table to the machine through the horizontal rectilinear rail, the approaching motion of the patient towards the machine, and the insertion of the limb to be examined therein, may be limited to a single degree of freedom, i.e. to a translation movement in said direction of insertion/extraction of the limb in and from the detection cavity.
Patient positioning, for performing examinations of different limbs, particularly arms and legs, may be obtained by simply rotating the examination table about the vertical axis.
The examination table according to the invention is particularly provided in combination with a Nuclear Magnetic Resonance image detecting machine having a tubular detection cavity, i.e. of the type for alternatively detecting images of different parts of a leg and foot, and of an arm and hand. Here, the construction described above is notably advantageous. The guide and hence the translation movement of the examination table in the direction of insertion/extraction of the body part in and from the detection cavity are oriented parallel to the axis of the tubular detection cavity and are contained in the vertical plane also containing the central axis thereof. In order to examine one leg or one arm, for example a knee or a foot and one hand, a simple rotation of the examination table is needed, in the first case with the longitudinal axis parallel to the translation direction, and in the second case in one of the two opposite positions transverse, particularly perpendicular to the translation direction. Further, the overturning footrest allows the patient to take a sufficiently comfortable position, so that he can keep the part under examination still, be it a part of an arm or of a leg. During the examination of arm parts, the footrest may be turned outwardly into the operating position, while, in order to examine a leg part, especially a knee, it must be turned into the retracted position, substantially flush with the examination table end facing the detection cavity. In this way, the examination table may be approached to the cavity to the extent required to bring the knee in the imaging zone, without forcing the patient to take an uncomfortable position.